In comments on my recent post on Negative Ion Therapy, George asked what I thought about the "Forest AC" Air Conditioning System his Nissan vehicle is equipped with. I started composing comments a few times and ended up losing them b/c I closed the browser window and got a bit distracted by a wound-licking omega animale yesterday ;-) So I decided to make a blog post where I can imbed pictures, etc., since I was reconstructing the response anyway.
I'm only going to address this part of the system:
The Forest AC's new-generation plasmacluster ion system generates and supplies plasmacluster ions (through ventilation system) at higher densities than previous systems. These ions maintain cabin air quality, not only improve reduction of airborne microbes, also minimize adhere [sic] odors on the interior trim surfaces (odor substances are destroyed by OH radicals produced from the ions).
This Plasmacluster Technology was developed by Sharp, and is available in home "ionic air purifiers" (that are quite pricey). Here is the graphic for what they claim happens
I'm having no luck tracking down the technology used to generate the ions per se, (OK, it's not a priority for me so I didn't spend much time, but ...) , but this perplexes me. The O2- as shown is confusing, but since they show ions as spheres and molecules as clusters of spheres, I presume these are oxide ions, oxygen atoms that have taken on 2e's to have a -2 charge, and not some negatively charged diatomic oxygen molecule. I would be interested to know how they create airborne oxide ions. Before going further, I find the mention that
"[these ions are] the same positive and negative ions that occur in nature" ... and from their literature:
"Plasmacluster Ions are the same type of airborne ions that occur in nature, and their working mechanism is fully understood. Therefore, their safety is ensured."
to be marketing gobbledegook at best, and downright misinformation at worst. Yes, ions are natural, but in their action in different environments and concentrations by no means "ensures safety"!! Consider that both the hydrogen and the sulfate ion are natural, and well characterized, and have some important roles in human metabolism. But as Wheat Belly will tell you, they're dangerous stuff if it comes as sulfuric acid!
Back to the chemistry claims, presuming this system releases H+ and O-2 ions into the air as claimed. Despite the fact that their literature touts "positive and negative ions [that] purify the air", they focus only on the negative oxide ions in their mechanism. Here's what they claim happens:
- When the O-2 ion contacts a microbe or virus it is transformed into the "powerful" hydroxyl radical.
- This radical then reacts with a hydrogen atom that is covalently bonded to some molecule in the virus/microbe/spore. This presumably damages the virus/microbe/spore and forms water.
I'm not seeing this, and here's why. At right are the "electron dot" structures of the various species involved. A neutral H atom has 1e, a neutral O atom has 6e's. As I've discussed previously here and here, oxygen can form either ionic or covalent compounds -- it either takes on two e's to become a -2 anion, or it shares it's two unpaired valence electrons with one or two other atoms in covalent bonds. In this scenario, we're starting with the oxide anions -- these are very stable entities despite their charge. It makes more sense from every standpoint for the oxide ion to be electrically attracted to any positively charged particle it comes in contact with to form a "neutral union" ... and they live happily ever after, end of story. I am at a loss as to why it doesn't just react/combine with one or two H+ ions in the plasmacluster ... they would be more attracted to these oppositely charged particles than neutral entities.
But let's presume for the sake of argument that it needs a "docking site" to combine with hydrogen. Again, they don't say where this H comes from, but it doesn't matter. An oxide ion with its stable 8e's combining with a H+ ions that contributes no electrons, form a hydroxide ion with 8e's as shown horizontally at right. (FWIW, this is called a "coordinate covalent" bond where the oxide ion donates both electrons in the bonding pair, but once donated, the pair is shared -- albeit unequally -- by the O and H atoms.) It would make no sense for the "transformation" into hydroxyl radicals as claimed (down arrow) to occur. The hydroxide ion is a stable polyatomic ionic species, in one out of every 10 million molecules of water, a hydroxide goes it alone. It is stable because the O has its octet of electrons, and enough electron drawing power to sustain the negative charge on the molecule. For a hydroxyl to be formed, essentially after combining with a hydrogen, the molecule ejects an electron off into outer space?? Not likely because (1) electrons don't just do that except under very extenuating circumstances, and (2) that electron is tightly held by the oxygen atom and it has no reason to want to release it.
In the second step they are saying that the radical rips a covalently bonded H atom (with its electron) from the bug to form water. This step is feasible, but only if the radical is formed in the first place. Far more likely the hydroxide "takes on" one more H+ ion to form the neutral water molecule. Which is what I believe occurs. The bottom line here is that the electrons don't add up. Every oxide ion generated has a surplus of electrons, and 8 in total. Those electrons are not accounted for in the formation of a hydroxyl radical. The only possible "sink" for those electrons that supposedly escape the oxide ion as it is transformed, would be the H+ ions, and if the oxide ions didn't combine with those in the first place, its even more unlikely this whole scenario occurs with that spare electron finding a floating proton.
The only things left up for debate, then, are:
- What is the source of the two H+'s in the process -- do they come from the H+ generated in the plasmacluster, or are H's ripped from covalent bonds (leaving the electron behind) on a virus/microbe/spore?
- If the H is ripped from the relatively enormous molecules, does this alter the mechanical integrity of the entity?
- If the H is ripped from the relatively enormous entities creating a -1 net charge, can that be "cleaned" from the air?
- The H's probably come from the air if there's sufficient concentration of all particles for collision and combining to occur.
- If you rip a proton from a molecule containing many hundreds of protons, it is not likely to change much in terms of structural integrity.
- If you have a -1 charge on a large mass and try to attract these to a positively charged plate, for example, the remaining -2 charged relatively tiny oxide ions are going to high-tail it to that very same plate. You'll "clean" the plasmacluster before you snag bugs!
I'll close with some ancillary comments. First, will such systems generate sufficient ions to make a difference? According to Sharp's literature, virus suppression has been demonstrated in a 1 cubic meter box -- I'd say that's probably the volume of the space surrounding one seat in a car. But at least we're talking small spaces with additional air movement, so it is possible that these systems in vehicles can work to generate sufficient ions. I'm highly skeptical of the ones to be used in homes.
Secondly, and more importantly IMO, are they safe? I mentioned ozone generation in my previous post, and it's comforting to know these are low ozone producing units. But I'm curious as to the effects of the oxide ions themselves. Also, if I'm missing something obvious, and hydroxyl radicals are really formed, what's to say they won't have detrimental effects on your cells, specifically the cells lining your respiratory tract?
Therefore, my take on this is that it's a gimmick. They could never "sell" (as in convince people to buy) a unit that directly generated harmful hydroxyl radicals. So they are counting this claim that these harmful radicals are only created when the oxide ion contacts a bad bug particle, where it remains attached once transformed into the nasty hydroxyl radical, so it only does it's bad stuff to the bad bugs. Whether the systems generate equal amounts of H+ and oxide, or air enriched with these ions assists in respiration and/or somehow cleans the air I don't know. But I'm pretty darned sure that if it does anything it is not by the process/mechanism they are claiming.